Dr Greenhalgh's solution was to use a polymer gel-based resin that combines two networks of cross-linking structures, one that holds the material together and the other providing a conduit for charged particles.
The road scheme, the largest of its kind in Northern Ireland, formed part of a proposed key cross-border business route linking Dublin and the north west.
The 65-page document, signed in Belfast in 1998, led to the Northern Ireland assembly and executive being set up, new cross-border institutions involving the Irish Republic and a body linking devolved assemblies across the UK with Westminster and Dublin.